Preventing the Same Value from Being Entered in a TextBox

File teaching Preventing the Same Value from Being Entered in a TextBox operation.

Excel Preventing the Same Value From Being Entered in A Textbox

Users are prevented from entering the same value more than once. The TextBox control has been arranged so that it is checked at the time of entry. It is aimed to give a warning in case of incorrect re-entry. The aim of the study is to ensure reliability in form-based data entries.

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